The invention relates to a drive mechanism comprising at least three reciprocable pistons, each of which is provided with a drive rod which cooperates, via a drive rod head incorporating sliding bodies, with a plate which is mounted on a shaft which is rotatably journalled in the device. This plate is precluded from rotary movement with respect to the shaft, but can be tilted about a tilting axis which is transverse to the centre line of the shaft, and further means are provided for tilting the plate.
Drive mechanism of the kind forming the subject of the present invention are known in the technique as swashplate drives, which are particularly suitable for use in hot-gas reciprocating machines, pumps and compressors. The drive converts the reciprocating movement of the pistons into a rotary movement of the plate and the shaft connected thereto, or vice versa. The stroke of the pistons is determined by the distance between the drive rods and the shaft and by the angle enclosed by the plate and the shaft.
By tilting the plate about the tilting axis, the angle enclosed by the plate and the shaft is varied, and in this comparatively simple manner the stroke of the pistons can be varied. Thus, the power delivered by engines can be adjusted and the yield of pumps and compressors can be varied.
U.S. Pat. No. 3,511,102 describes a hot-gas engine whose power can be controlled by tilting the plate with which the pistons cooperate more or less. The tilting of the plate is effected by means of mechanical means, which makes the entire adjusting mechanism complex. The invention has for its object to provide a device of the kind set forth, wherein the adjustment of the plate is effected in a simpler manner.